Piazza, who will be the designated hitter for the Oakland Athletics, homered for the second straight game, connecting for a three-run shot in the first inning against his former team in Oakland's 8-7 victory over the San Diego Padres. He also hit a sharp single to left in the fifth.
"Mike has been on everything at the plate," manager Bob Geren said in Phoenix. "He's been feeling so good after three at-bats."
Wood, moving to the Cubs' bullpen, pitched in a spring training game for the first time in 12 days, throwing a scoreless inning as Chicago beat the San Francisco Giants 6-2.
Wood's layoff came after he strained his right triceps in his previous outing March 11. Whether he will start the season with the team or on the disabled list is still not decided.
"I feel like my arm is in great shape. The shoulder is fine," Wood said in Mesa, Ariz. "Everything feels great and that's all I'm worried about."
Wood, the one-time Cubs ace who is making his way back from a partially torn rotator cuff, will not be able to make back-to-back appearances, something manager Lou Piniella wants all his relievers to do before spring training ends.
"With Kerry that hasn't been the game plan, obviously," Piniella said. "The reason I say that is because he's had a couple of setbacks."
Geren and A's general manager Billy Beane don't plan to use Piazza even as an emergency catcher if they can help it.
"It's definitely a challenge," Piazza said of having more time on his hands and being judged only by his offense. "I'm starting to enjoy it. It's a change, but I'm just kind of adapting."
The news wasn't as good for Los Angeles Angels third baseman Chone Figgins, who is expected to be sidelined five to six weeks with two broken fingers on his throwing hand.
X-rays taken Friday revealed Figgins has fractures of the index and middle fingers on his right hand. He was injured in the fifth inning of Wednesday's game against Arizona in Tempe, Ariz., when a grounder hit by Conor Jackson bounced off his hand.
Figgins had said Thursday he hoped to return by opening day, but that was after X-rays revealed a fracture just above the first knuckle of his middle finger and didn't show the other break.
At Tampa, Fla., the Yankees' Chien-Ming Wang felt discomfort in his right hamstring during light running Friday. Wang, who tied for first in the AL with 19 wins last season, underwent treatment afterward, and Yankees manager Joe Torre was hopeful the injury wasn't serious.
"I've had no emergency calls," Torre said after the Yankees' 3-2 to Pittsburgh in Bradenton, Fla.
Andy Pettitte, another candidate to start on opening day for the Yankees, played catch for the first time since experiencing back spasms earlier in the week. Pettitte had been shut down since getting hurt while working out Monday. He still has some minor stiffness, but continues to improve.
"Definitely feeling better every day," Pettitte said. "I feel a lot better."
In Jupiter, Fla., Florida Marlins coach Perry Hill announced his retirement, ending a 14-year major league career during which he coached five Gold Glove-winning infielders.
At Fort Myers, Fla., Erik Bedard held Boston hitless for 4 2-3 innings and allowed one run and one hit. He struck out eight in five innings. Curt Schilling went seven innings for the Red Sox, allowing two runs and six hits.
At Port St. Lucie, Fla., Orlando Hernandez lowered his spring ERA from 10.50 to 5.25, allowing one unearned run in six innings against the Cardinals. St. Louis closer Jason Isringhausen tossed a perfect fifth, striking out one.
At Fort Myers, Fla., reigning AL Cy Young Award winner Johan Santana gave up two runs and four hits in five innings for the Twins.
At Viera, Fla., Washington's John Patterson allowed a run in four innings in his longest outing since injuring his forearm last July.
At Clearwater, Fla., Kyle Davies made his best case to remain in Atlanta's rotation, allowing three hits and a run in six innings. Also Friday, the Braves traded shortstop Tony Pena Jr. to Kansas City for minor league pitcher Erik Cordier.
At Peoria, Ariz., Felix Hernandez allowed four runs in six innings against the Angels and, after the game, Mariners manager Mike Hargrove announced Hernandez will start on opening day. Hernandez will join Dwight Gooden (1985) and Fernando Valenzuela (1981) as the only pitchers in the past 26 years who have started on opening day while just 20 years old.
At Tucson, Ariz., the Rockies said Troy Tulowitzki won the starting shortstop job over Clint Barmes and Josh Fogg would be the team's fifth starter.
At Winter Haven, Fla., Roy Oswalt prepared for his fifth consecutive opening day start with six scoreless innings, allowing three Indians hits.
At St. Petersburg, Fla., outfielder Jonny Gomes had three hits and four RBIs in Tampa Bay's rout of Cincinnati. Reds starter Aaron Harang gave up six earned runs on eight hits in six innings.